The property market plays an important role in the overall economic performance of Hong Kong. Housing is the most important form of savings for many households. The extremely volatile property market will create many social and financial problems. Thus the healthy and stable development of property market has been one of the goals of the Hong Kong Government. The housing price increases sharply in the past few years and it creates much negative tension in the society. The Hong Kong Government pledges to increase land supply and public housing to ease the property market. This thesis attempts to explore the impact of land supply and public housing program on housing price in Hong Kong. An aggregate housing model with three components is designed in which the land supply and public housing are incorporated. The results show that the public housing program has a negative impact on the housing price. The land supply will impact the housing price through increasing the future housing supply.